AIDS vaccine research shows hope

After spending two years studying the results of the largest AIDS vaccine trial ever conducted, researchers have discovered how the immune system reacted to the vaccine candidate RV144, providing a glimpse into how vaccines could be made more effective.

RV144 was shown to be 31 percent effective in preventing HIV infections in 16,000 Thai adults studied in a phase III clinical trial in Thailand. More than 16,000 adults were part of the study, making it the largest of its type ever conducted, according to CNN.

"What we now have are clues, why it might work," Dr. Carl Dieffenbach, the director of the Division of AIDS at the U.S. National Institute for Allergy and Infectious Diseases, said, CNN reports. "Something we haven't had over the last 30 years, so that's very important."

Though considered only moderately protective overall, researchers found clues as to why the vaccine worked in some and not in others. It is hoped that this information can help vaccine makers design future clinical trials.

The results were announced at the AIDS Vaccine Conference, hosted by the Global HIV Vaccine Enterprise and co-hosted this year by Mahidol University in Thailand, where the RV144 trial took place.

Dr. Barton Haynes, the director of the Duke Human Vaccine Institute at the Duke University School of Medicine, said that one immune response to RV144 led to vaccine efficacy, while the other led to the same protection rate as a placebo.

"We now have an informed hypothesis, we have signals,” Haynes said, CNN reports. “Now we know where we want to go."